Process of purifying and decolorizing saccharine or other liquids



(No Model.) 2 Sheets-Sheet l.

M; PRIDHAM. PROCESS OP PURIPYING AND DEGOLORIZING SAGGHARINE OR OTHERLIQUIDS.

Patented Deo. 15, 1896.

. l l l a l c n i 1 l J l l l l m: Norzavs paens no4 moro-Lomo.,wAsHxNnToN. o. cV

(No Model.) l 2 Sheets-Sheet 2.

M.. PRIDHAM. 1 PROCESS OP PURIPYING AND DEGOLORIZING SAGGHARINB 0ROTHER- LIQUIDS. No. 573,289. Patented Dec. 15, 1896.

1H: cams Pc'rsns co, PuoTaLlrHo., wAsmNmoN. o. c.

UNITED ASTATES `PATENT f PRICE,

MARSHALL PRIDIIAM, CF PHILADELPHIA, PENNSYLVANIA, ASSIGN OR, BY DIRECTAND MESNE ASSIGNMENTS, TO THE ELECTRIC RECTIFYING AND REFINING COMPANY,OF CAMDEN, NET JERSEY.

PROCESS F PURIFYING AND DICOLORIZAING` SACCHARINE OR OTHER LIQUIDS.

SPECIFICATION forming part of Letters Patent Nd. 573,289, dated December15, 1896. Application filed September l0, 1896. Serial No. 605,441.(Specimens.)

sugar, and othersaccharine solutions, or otherliquids containingorganic, nitroge'nous or mechanical impurities, such as Water, the.,`

Wliereby the mechanical impurities and organic substances containedtherein may be efficiently and economically removed therefrom, andwhereby the said liquids may be clarified and decolorized to the highestdegree.

In the present state of the art the process of removing the mechanicalimpurities and organic substances 'from saccharine liquids in generaluse necessitates the employment of the bagflter process, which iscumbersome, Wastef ul, and expensive both as to time and labor required,Whereas in my process I propose to dispense entirely with this bagfilterprocess, accomplishing the same or better results in minutes as comparedto hours now required, thus reducing the expense in this step of thetreatment to an extent of seventy-five per cent. at least. A

Again, in the present method of clarification and decolorization ofsaccharine liquids animal char is universally used for filtration, andin this char process of filtration enormous quantities of Water aredemanded daily, the

char must be revivitied daily by being reburned or recalcined,necessitating the use of large quantities of coal for this part of theprocess alone and requiring the employment d uring the Whole twenty-fourhours of the day of anumber of hands, While the maintenance of the charfilter by the frequent rebuilding of the char coal-kilns during the yearinvolves large expenditures of time, money,`a nd labor, Whereas by myprocess offclarification and decolorization this step ofchar filtrationis entirely dispensed with, thus obviating the expenditures incident tothe use of this old step. v

' With these factslin View the object of my invention is to provide anew process for treatment of saccharine liquids whereby the eliminationof impurities, organic and nitrogenous substances, from saccharine andother liquids and the clarification and decolorization ofthe same may beeffected by electrolytic action and by subjecting the liquids to theaction of ozone gas tn vacuo or in air, and by the combined action ofozone gas and the oxidsand oxyhydratcs of metal developed byelectrolysis.

By the use of my process the fungi Scc- C71 (Womit/ces cerevesz'ce,Pefncllz'um g'lctucmtm, and fungi of all descriptions are destroyed, theinversion in sugar is prevented, and fermentation in cane, beet, andsorghum sugar, raw sugar, syrups, molasses, dextrose, levu.- lose, andgluclose is e'ffectually arrested and prevented.

In carrying out my process I may treat the saccharine liquids upon theplantation Where the cane-sugar or saccharose (CWHQQOH) is obtained fromexpressed juice of the cane, (Sacchmam QZicincrztm/J beets, and sorghum, so as to prevent or arrest fermentation, and combine this treatmentat the same place With a further treatment for the purification,clarification, and decolorization of the liquids, or I may merelysubject the liquid for treatment to the first step of the process forthe purpose specified and complete the treatment at the refinery toWhich the treated liquids are sent, or the Whole process may be carriedout at the refinery, and when describing my process I will preferablylocate the steps at one place, illustrating the mode of carrying out thetreatment by means of apparatus grouped at such place, with the distinctunderstanding that I do so merely for the purpose of a brief andluciddescription of the process and not for the purpose of limiting theprocess tothat extent.

In the treat-ment of saccharine liquids under my process I proceed byintroducing a sufficient quantity of the liquid into a suitable tank orvessel provided with plates of suitable material forming positive andnega- IOO tive electrodes connected, preferably,to a generator forcreating a direct current of electricity. This tank is connected with areservoir containing ozone gas derived from a suitable source, and isalso connected by piping to a vacuum-pump or air-exhauster, valves beingprovided in all of the pipe connections with the tank, as desired. Thetank is preferably made air-tight, so that a vacuum or partial vacuummay be created therein before or after the liquid is introduced, and ofcourse the said tank must be lined, so as to prevent oxidation and theescape through its walls of the ozone gas. The air in the tank andentrained in the liquid is `nowexhausted by the vacuum-pump, and whena-suficient vacuum/ is obtained the current of electricity is turned onand the ozone is admitted to the tank, the resul-t 4of which admissionis that the ozone permeates thoroughly the liquid and moves in intimatecontact with every part thereof, -fillin g the spaces previouslyoccupied by the air. In order to effect the most thorough contact w-ithevery part of the liquid, the ozone is preferablyintroduced atthe'bottom and sides of the tank. The degree of partial vacuummaintained may vary, the general rule `bei-ng that the nearer a perfectvacuum is-a-pproached the more rapid is the treatment.

Mfhile it is not absolutely'necessary to heat the liquid beforesubjecting it to the action of the electric current and the ozone gas, Ishould state that in the .treatment of all sac,- charine liquids, exceptthe vjuice expressed from cane, beets, or sorghum, it is advisable toheat the liquid from to 90 centigrade, according to the gravity andcoloring of the liquid, the very dark liquid receiving most heat. Theobj ect of thus heating` the liquid, such as sugar solutions,molasses,.&c., before treatment by electrolysis is to render the samereadily oxidizable -by electrochemical action in order to lassist thedeposition of organic and nitrogenous matter, which is particularlydesirable in liquids containing albumen that coagula'tes and carrieswith it the impurities.

If the gravity of the liquid is too great, the work of removing themechanical impurities is greatly retarded, and consequently the.decolorizing action is retarded, and in order to vovercome this Ipreferably reduce the gravity by the addition of water, which isafterward removed by addition of heat or by electrolysis, and in thisconnection I may state that lI [in d that where the gravity is below 400Eaum the liquid may be treated without the reduction stated, while abovethis limit it is advisable to reduce the gravity to a point between SOOand 40 Baume.

Under the electrolytic action set up by the current of electricitypassing from the positive electrodes through the liquid to the negativeelectrodes the gases evolved from the water contained in the liquidattack the organic and nitrogenous matter contained therein and causethe said impurities to be oxidized by or to form other electricalcombinations with the electrodes themselves.

such gases, such products being deposited or precipitated, so as to freethe liquid therefrom. I find that the electrolytic action is greatlyassisted by the use of aluminium electrodes, since the action of thegases evolved under the electrolysis is' to attack the aluminium of theplate, forming aluminium hydrate, which is a decolorizing agent forsaccharine liquid, and I therefore greatly improve this action by usinga positive plate in the form of a grid. or perforated, pitted, orcorrugated conductor of aluminium, or other suitable material, havingthe pits, corrugations, or openings filled with aluminium hydrate. Inthe electrolytic action the electrolytically-developed aluminium hydrateis deposited upon the cathode and has a decolorizing effect upon theliquid under treatment, and after such treatment this aluminium hydrateis recovered by washing the plates with water, collecting the washingsin .a suitable receptacle, from which the foreign matter is thenremoved, and the aluminium hydrate finally precipitated and recoveredfor further use. I mention this not as a limitation of the broadinvention embodied in my process, but as defining a preferable form ofpositive electrode, by the use of which the electrolytic action upon theliquid may be greatly facilitated.

I have found that good results may also be obtained by the use of zincelectrodes and zinc oXid when complete decolorization yis not necessary,and as the zinc oXid is insoluble Zuse `the zinc plate and the zinc oxidwhen possible. Any other suitable metal plate and compound capable ofVdecolorizin g the liquids maybe used, though 'I have found the twomentioned to be preferable. The negative plate, in such cases, ispreferably made of a neutral material, such as carbon, and is providedwith pits, openings, or cells, in which the foreign matter will bedeposited, together with the hydrates of aluminium or zinc oXid, thatare subsequently recovered, as above delined.

The action of ozone gas upon the impurities of the liquid is toimmediately oxidize them, thereby aiding in the deposition of theimpurities by the electrolytic action, thus freeing the liquid from thesaid impurities, and at the same time the ozone, in the first treatmentof the liquid, clarifies and decolorizes the same. The ozone gas ispreferably introduced into the treating vessel in such manner as to passthrough the liquid between the electrodes, and also to come into contactwith The treatment in this one tank is generally found sufficient forall purposes, particularly when the ozone is of a high degree ofstrength, but when ahigh IOO in water or saccharine liquids it can bere- IIO degree of decolorization is desired the treated liquid in thefirst tank may be delivered into a second tank and there subjected tothe action of the ozone gas tu tacito, the said tank being connectedwith the vacuum-pump and preferably located on a lower level from thefirst tank, so that liquid may HOW thereinto by gravity. In this secondtank a suitableV agitator may be placed for thoroughly agitatingY theliquid under treatment, thereby inducing a more intimate and thoroughcontact of the liquid with the ozone. B y the employment of the vacuumin connection with the ozone I am enabled to charge the liquid with amuch larger amount of gas than would otherwise `be possible, and forthis reason I pre- .fer to use the vacuum in all the treatments.`

While in all cases I prefer to use the vacuum step, I may sometimes,when circumstances require it, omit the vacuum step. In such cases theelectrolytic action should still be used in connection with the ozonetreatment, for the reason that the oxidizing action of the gas uponcertain oxidizable impurities renders the electrodeposition of saidimpurities more complete and speedy.

lVhile it is preferable to first establish the vacuum or partial vacuum,introduce the ozone gas, and then commence the electrolytic treatment,for the reason that the action of the ozone upon the liquid is greatlyincreased by the removal of the air, I wish it understood that myprocess is not limited to this order of procedure, as the steps may becarried on simultaneously without seriously 1 impairing the efficacy ofthe whole process.

In carrying out the process as above described I find that usually itrequires about ten minutes to complete the treatment with the currentvarying in strength from five to ten volts and in quantity from fifty tosixty amperes per square meter of electrodes used.

lVith this elucidation of my process I will now describe one form ofapparatus in which it may be carried out, premising that the form andarrangement may be varied as desired to suit the surroundingcircumstances, and the character of the electrodes, the strength of thecurrent of electricity, the amount of the ozone gas, &c., and thepreliminary treatment of the liquid by heating or by adding the waterfor reducing the gravity 0f the liquid being susceptible of variationaccording to the character of the liquids treated in each case.

In the drawings I have shown two arrangements of apparatus, in one ofwhich the tanks are so arranged that the liquid may flow from one to theother by gravity, and in the other form the tanks are arranged on thesame level, so that pumps are used to carry the liquid from one tank tothe other.

Referring to the drawings, Figure lisa sectional side elevation of oneform of apparatus for carrying out my process.` Fig. 2 is asideelevation of a modified form for carrying out my process. Fig. 3 is atop plan vieuT of the `view of the agitator.

same, partly in section. Fig. 4 is a detail In all of the views the samecharacters relate to the same or'corresponding parts, and referringfirst to Fig. l, A designates a tank of any suitable size and shape,preferably of rectangular form, to which tank is connected -the pipe afor introducing therein the liquid for treatment, Which pipe is providedwith a valve a', the said pipe preferably terminating in a suitableinjector I-l, to which is also connected a pipe c, leading from areservoir C, containing the ozone gas derived from a suitable generator,connected to said reservoir by a pipe c', provided with avalve c". A

vacuum-pump D or air-ej ector of any suitable,

form is connected by a pipe d, provided with a valve el', to the tank A,whereby a vacuum or partial vacuum may be established in the tankfA, asdesired,'the connections between the air-exhaust d and the tank beingshown for convenience at the left-hand end of the tank A.

Suitably supported within tank A are the electrodes E E', Figs. 1 and 3,the former of which are the anodes and the `latter the cathodes, therebeing shown three of such cathodes and two anodes connected,respectively, to the binding-plates c and e'. Mounted in the cover A. ofthe tank A are suitable binding-posts c, preferably insulated from thetank, the lower ends of the metallic conductors of said posts beingadapted to dip into a groove e, lled with mercury, arranged on the upperedge of one or more of the electrodes, or upon the binding-plates c e",connecting the different electrodes in series. These electrodes arearranged a sufficient distance apart in the tanks, so that they canbereadily cleansed and renewed without removing them from the tank. Theelectrodes in the tank are connected, through the respectivebinding-posts and line-Wires, `to a suitable generator F, (shown inFigs. l and 3,) preferably a direct-current generator, between which andthe tank, of course, there Will be placed the usual accessories forchanging the strength of the current, cutting it oif, dac., such asswitches, transformers, and the like, (not shown `in the drawings,) asthey form no part of my invention and may be of any suitable design.

One end of the tank A is preferably provided with a depressed portion G,forming a well into which the precipitated impurities may be removedfrom time to time.

From the foregoing description of the construction, taken in connectionwith the description of my process hereinbefore set forth, the manner'ofusing the apparatus thus described for carrying Yout my process will bereadily understood Without further description.

Generally, as before indicated, a treatment in this tank alone will besufficient, but in some cases,where it is desired to effect a highdegree of clarification and decolorization,I

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employ a second tank B, connected to the tank A bya pipe b, providedwith a valve Z1. This tank B, for the second treatment of the liquid, isconnected by pipe CZ"to the vacuumpump or air-exhauster D, the said pipebeing provided with a suitable valve ttl, whereby a vacuum may beestablished in said tank. In the top of said tank, which is secured tothe body with an air-tight joint, is preferably mounted aspraying-coneI, adapted to be rapidly rotated by a driven pulley J, operated from anysuitable source of power, the discharge-pipe Z) from the tank A openingin front of said spraying device in tank B, on the other side of whichsprayer is preferably arranged the inlet end of one branch 0" of thepipe C', leading from the ozone-reservoir,

thus discharging the gas against the spraying device at the same timethat the liquid from the tank A is discharged against said device on itsopposite side as said sprayer is rotated rapidly, thereby breaking upthe liquid into tine particles and insuring a thorough and intimatecontact of the gas with said particles; and to further insure theintimate mixture of the gas and liquid in this tank two other valvedbranch pipes ci" c" conduct the gas into the tank, the one at one ormore points at the side of the vessel or tank B and the other throughthe bottom.

In order to secure the highest degree of efficiency, I preferably mountin the bottom of the tank an agitator K, consistingr of a chambered hubL, having projecting therefrom a suitable number of blades or vanes Z,preferably four in number, the said hub being rotatably mounted upon theupper end of the pipe c, extending upwardly through the bottom of thetank B and provided with orifices vn, opening into thehollow hub L.Secured to the face of the blades Z are perforated pipes Z',communicating with the hub L, through Which pipes the ozone gas hasready access to the interior of the tank B. The agitator K is rotated inany suitable manner, for example, by means of the pulley M, mounted uponthe extension m of the hub L, passing downwardly through the bottom ofthe tank, all of the joints being suitably packed to prevent the escapeof gas or liquid.

W'hen it is desired to continue the treatment by ozone gas, thevacuum-pump is connected with the tank B and a partial vacuum createdtherein, and the liquid then allowed to flow by gravity4 from the tank Ainto the tank B, the ozone gas being at the same time turned into saidtank through the various pipes mentioned, the sprayer and agitator beingrapidly rotated, so that the liquid in said tank is subjected to anintimate and thorough mixture With the gas, and after a short time thesaid liquid is thoroughly clarified and decolorized. The tank may thenbe ent off from the liquid and gas supply, the sprayer and agitatorstopped, and the contents drawn off through the discharge-pipe N.

In Fig. 2 I have shown a modified arrangement in which the tanks,instead of being located on different levels, are on the same level, inwhich case the liquid is pumped into the tank A by means of a pump O,either centrifugal, reciprocating, or other form, and from the tank Athe liquid is pumped into the tank B by a pump P, the other partsremaining precisely the same as defined.

Vhile I have shown the electrodes placed in the tank A only, if founddesirable the second tank may also be provided with electrodes and theelectrolytic action continued therein, as Well as the ozone treatment,but generally the first electrolytic treatment will be sufficient.

In the use of my invention upon the plantation I find that by subjectingthe liquid eX- pressed from the juice to treatment in the first tank Iam able to cause the removal of albuminous and WaXy matters having atendency to ferment Without the addition of the milk of lime and heat,as noW generally practiced to prevent and arrest fermentation. I alsound that I can prevent the tendency of inversion in sugars, so that theliquid may be subsequently treated ou the spot or transported forfurther treatment Without danger of fermentation during transportationor danger of inversion in the subsequent steps for crystallization. Inthis connection I may state that I have found by experiment that theinversion that sugar undergoes in the presence of Water is but partlydue to the influence of mold or fungi and is largely due to the factthat Water acts as an acid, hydrates the cane-sugar in the presence ofair, and consequently by my vacuum, ozone, and electrolytic treatment Ientirely destroy this tendency.

I should add that in some grades of syrups evidence of granulation maysometimes appear, in Which case the common expedient of adding asufficient quantity of glucose to 0bviate this tendency may be adopted.

I do not herein claim the apparatus disclosed, as that forms thesubject-matter of a separate application filed by me September l2, 1896,Serial No. 605,631.

Good results, as compared With ordinary bag-and-char filtration, may beobtained by subjecting the saccharine liquids first to electrolyticaction and subsequently to treatment with ozone gas, and in anapplication for patent iiled by me on the 15th day of October, 1896,Serial No. 608,988, I have described and claimed such process. Muchbetter results are, however, obtained by subjecting the saccharineliquids simultaneously to the electrolytic action and to treatment Withthe ozone gas with or Without subsequent treatment With ozone gas, andmy present application is therefore based upon this form of the process.

Having thus described my invention, I claim and desire to secure byLetters Patentl. The herein-described process of purify- IOO IIO

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, ing saccharine or other liquids, which consists y in subjecting theliquid to the direct action of an electric current and simultaneouslypassing ozone gas through the liquid, substantially as specified.

2. The herein-described process of purifying saccharine or other liquidswhich consists in subjecting the liquid in tacito to the direct actionof an electric current, and simultaneously passing ozone gas through theliquid, substantially as specified.

3. The herein-described process of purifying saccharine or other liquidswhich consists in subjecting the liquid to the direct action of anelectric current and simultaneously passing ozone gas through theliquid, and subsequently subjecting the liquid so treated to furthercontact with ozone gas, substantially as specified.

4. The herein-described process of purifying saccharine or otherliquids, which consists in subjecting the liquid, While in a state ofagitation, to the action of ozone gas, and simultaneously subjectingsaidliquid to the direct action of an electric current, substantially asspecified.

5. The herein-described process of purifying saccharine or other liquidswhich consists in first reducing the gravity of said liquid by theaddition of Water, and heating the same, and then subjecting the liquidso treated to the direct action of an electric current, andsimultaneously passing ozone gas thro ugh the liquid, substantially asspecied.

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7. The herein-described process of purify ing saccharine or otherliquids, which consists in subjecting said liquid n vacuo to the actionof electrolytically-developed aluminium hydrates, and simultaneouslypassing ozone gas through the liquid, substantially as speciiied.

8. The herein-described process of purifying saecharine or otherliquids, which consists in subjecting said liquid to the action ofelectrolyticallydeveloped metallic decolorizing compounds,andsimultaneously passing ozone gas through the liquid, substantially asspecified.

9. The herein-described process of treating saccharine or other liquids,which consists in subjecting said liquid t'nodcuo t0 the action ofelectrolytically-developed metallic decolorizing compounds, andsimultaneously passing ozone gas through the liquid, substantially asspecilied.

In testimony whereof I have signed my name to this specification in thepresenceof two subscribing Witnesses.

MARSHALL PRDHAM.

lVitnesses S. A. TERRY, M. H. MILES.

